In recent years, photoelectric elements have been used as, for example, power generation devices by photoelectric conversion, such as a photovoltaic cell and a solar cell, light-emitting devices such as an organic EL device, optical display devices such as an electrochromic display device and electronic paper, and sensor devices sensing, for example, temperature and light. Among them, a pn-junction device has been put into practice as a photoelectric element such as a solar cell. In addition, various photoelectric elements have been studied based on photoelectrochemistry as disclosed in Japanese Patent Publication No. 2664194 (hereinafter called literature 1) and other literatures. The photoelectric element is produced by interposing a charge transport layer such as an electrolyte between a first electrode with a semiconductor and a second electrode. The semiconductor typically supports a dye as a photosensitizer, and the photoelectric element is accordingly used as a dye-sensitized solar cell. Applying light to the semiconductor causes the semiconductor to generate charges; the charges move through the charge transport layer; and electricity can be extracted to the outside through the first electrode with the semiconductor as the negative electrode and through the second electrode as the positive electrode.
Although such a photoelectric element is formed so that charges generated from the semiconductor move through the charge transport layer as described above, the photoelectric element has insufficient conversion efficiency from light applied to the semiconductor to electricity extracted to the outside.